diff --git a/devel/readline/Makefile b/devel/readline/Makefile
index 4732dff1c9f1..0a29786623fb 100644
--- a/devel/readline/Makefile
+++ b/devel/readline/Makefile
@@ -1,5 +1,6 @@
 PORTNAME=	readline
 PORTVERSION=	8.2.${PATCHLEVEL}
+PORTREVISION=	1
 CATEGORIES=	devel
 MASTER_SITES=	GNU
 DISTNAME=	readline-${PORTVERSION:R}
diff --git a/devel/readline/files/patch-clang18 b/devel/readline/files/patch-clang18
new file mode 100644
index 000000000000..f019f4ddb4a9
--- /dev/null
+++ b/devel/readline/files/patch-clang18
@@ -0,0 +1,28 @@
+--- readline.h.orig	2024-09-21 16:56:41 UTC
++++ readline.h
+@@ -407,7 +407,7 @@ extern int rl_message (const char *, ...)  __attribute
+ #if defined (USE_VARARGS) && defined (PREFER_STDARG)
+ extern int rl_message (const char *, ...)  __attribute__((__format__ (printf, 1, 2)));
+ #else
+-extern int rl_message ();
++extern int rl_message (void);
+ #endif
+ 
+ extern int rl_show_char (int);
+--- rltypedefs.h.orig	2021-01-22 15:04:18 UTC
++++ rltypedefs.h
+@@ -32,10 +32,10 @@ extern "C" {
+ #  define _FUNCTION_DEF
+ 
+ #if defined(__GNUC__) || defined(__clang__)
+-typedef int Function () __attribute__((deprecated));
+-typedef void VFunction () __attribute__((deprecated));
+-typedef char *CPFunction () __attribute__((deprecated));
+-typedef char **CPPFunction () __attribute__((deprecated));
++typedef int Function (void) __attribute__((deprecated));
++typedef void VFunction (void) __attribute__((deprecated));
++typedef char *CPFunction (void) __attribute__((deprecated));
++typedef char **CPPFunction (void) __attribute__((deprecated));
+ #else
+ typedef int Function ();
+ typedef void VFunction ();